On today's episode of the 5 Things podcast: Need a pick-me-up today? Watch a video of a smiling dog – it should do the trick. But is your dog really "smiling" in the way humans understand it? And if ...

When we’re happy, the corners of our mouths move out and up, our cheeks lift, and the skin around our eyes crinkles. And researchers now say that process can be reversed: force the muscles of the face ...